Indirect illumination



Sept. s, 1925. 1,552,957

L. ROTH INDIRECT ILLUMI NATION Filed March 13, 1922 Patented Sept. 8, 1925.

UNITED STATES PATENT OFFICE.

LOUIS ROTH, OF NEWYORK. N. Y., ASSIG'NOR T0 STERLING BRONZE COMPANY, OF NEIV YORK, N. Y., A CORPORATION OF NEW YORK.

INDIRECT ILLMINATION.

Application filed March 13, 1922. Serial No. 543,392.

To all whom it' may concern.'

Be it known that I, Louis RorI-r, a subliect of Austria I-Iungary, residing at Newl York, borough of Manhattan, and State of New York, have invented a certain new and useful Indirect Illumination, of which the followingl is a specification.

This invention pertains to the illumination of rooms or apartments by indirect lighting obtained by utilizing the ceiling as a medium for the diffusion of light rays the source of light being a lamp housed within a suspended fixture.

The object is twofold; first, to reflect the rays from an encased lamp toward the ceiling whence the light is in the main diffused within the room, and, second, to direct and control some of the light rays for the illumination of a suspended bowl or dome without the exposure of a more or less intense spot of light centrally of said bo-wl or the creation ofl that shadowy effectI on the surface of the bowl known in the indirect illumination art as a silhouette According to this invention a reflector is employed in a position intermediate an inverted dome and a source of light, such as a lamp, said reflector being of an opaque nature for the major part of its area and being provided with a transparent port-ion for a. definite part of its surface. The re- Hector is in spaced relation to the dome or bowl, and the space intervening said bowl and the reflector is closed by an opaque cover plate the under surface of which is in such relation to the transparent portion of the reflector that the light rays passing through said transparent portion are deiiected within the globe to effect the illumination thereof by a soft glow free from the shadowy effect or silhouette and extending uniformlyT throughout the area of said globe. kThe cover plate in my fixture performs the functions of a dust cap to exclude the lodgment of dust within the globe and a refiector for diffusing some of the light rays to effect uniformity in the illumination of said globe.

Other functions and advantages of the invention will appear from the following description taken in connection with the drawing, wherein the figure is a view partly in elevation and partly in vertical section of fixture for obtaining indirect illumination in accordance with said invention.

In a practical embodiment, a dome or bowl A is supported by a carrier member or ring a in a stationary position by a flanged plate B from a spider C of a hanger D, the whole constituting a fixture which may be of any desired construction and ornamented or finished as required. As shown, the carrier member or ring a is hingedly connected at a to the ianged plate and is held in an operative position by an appropriate latch b, whereby the bowl may be'dropped down with a pivotal movement with the hinged connection a. as the axis of movement, thus permitting free access to the interior surfaces of certain members coinprised in the fixture, said bowl being retained in an elevated operative position by the latch.

The important part of my invention is the reflector E constructed as presently described and co-operating with the bowl or dome for suppplying thereto light in such manner as to illuminate said bowl for the entire surface thereof and without the production of a shadowy effect or a spot-like area of concentrated light. Said reflector is composed of material suitable for the purpose, preferably glass, the interior surface is silvered at e for the entire area including the bottom portion except for a relatively narrow band F at or adjacent the upper portion, and the exterior surface is coated at f with a light refiecting substance. The mirror like surface e is or may be produced on the interior of the refiector in any manner or by any means known to the art, but according to this invention it is desirable to extend said mirror surface over the entire area of the reflector except for the relatively narrow band or area F. The reflector thus obtained is opaque except for the area F, thus precluding the passage of light through the central bottom portion of the mirror and the production on the bottom portion of the bowl A of a spot or area of concentrated light rays from the lamp G. As described, the silvered surface e and the opaque coating f donot extend to the top edge of the reflector; on the contrary, said silvered coating and the opaque coating terminate at lines well below the top edge of the glass material, thus leaving a well defined area Foftransparent or translucent glass material at the upper portion of the reflector.

H is a cover plate `or dust cap composed of metal or other material suitable for the purpose, attached to the carrier a and to the reflector for supporting said reflector in an operative relation to the bowl or dome. As shown, the cover plate voccupies a horizontal position over the space intervening the top edges of the globe and the reflector, the outer edge of said cover plate being embraced by the carrier ring c so as to support the cover plate in fixed relation to the edge of the bowl. The inner edge of the cover plate is attached to an offset ring 7L which is attached in a suit-able way to the top edge of the reflector. Said cover plate acts as a member for mounting the reflector within the dome of the bowl, and as a dust cap for excluding dust against entry into the bowl so as to obscure the inner surface thereof by a coating of dust; but a primaryfunction of the cover plate is to reflect the light rays passing through the area F downwardly into the bowl or dome, for which purpose the under surface of the cover plate is provided with a coating It. The coating f on the outer surface of the reflector, and the coating 7L on the under surface of the cover plate, may be of any material suitable for the purpose, such as white paint, or the like, applied in a desired manner.

The hanger D with spider C are or may be of desired constructions, whereas lamp G is the usual incandescent electric lamp now commonly used in electric lighting fixtures.

In the service of the fixture, with current flowing through the lamp, the light rays striking the silvered surface e of the reflector are thrown upwardly against the ceiling or other surface, and are thus diffused in a manner similar to the usual indirect illumination. The light rays, or rather some of them, pass through the transparent area F of the reflector and strike the reflecting surface 7L of the cover plate, being reflected thereby in a downward direction for the illumination of the dome or bowl with a soft diffused light. The light rays passing into the bowl are reflected by the coating f on the exterior surface of the reflector, and the light thus supplied at the top portion of the bowl is controlled for the illumination of said bowl with a soft diffused light over its entire area, free from a shadowy effect or silhouette and omitting a spot or area of concentrated light at the middle portion of the bottom so objectionable in some of the prior fixtures employed for indirect lighting.

Ha-ving thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

l. In a lighting fixture, a bowl, a hollow reflecting member positioned therein, said hollow reflectingmember having for the major part of its area a coating by which the light rays are directed upwardly and that part of said hollow member above the reflecting surface being composed of transparent material through which the light rays are free to pass into the bowl and an annular reflector closing the space between the bowl and the reflector member against the ingress of foreign substances and serving to direct light rays between said bowl and reflector member and through the bowl after such rays have been passed through the transparent area of the reflector member.

2. In a lighting fixture, a bowl, and a hollow reflecting member positioned therein, said hollow reflecting member having on its exterior surface an opaque coating and on its inner surface a coating functioning as a reflecting surface, said coatings on the respective surfaces covering the major area of the hollow member and the `upper part of said hollow member being composed of transparent material through which light rays are free to pass to the inside of said bowl.

3. In a lighting fixture, a bowl, and a hollow reflecting member positioned therein, said hollow reflecting member having for the major part of its area a coating by which the light rays are directed upwardly and that part of said hollow member above the reflecting surface being composed of transparent material through which the light rays are free to. pass into the bowl, and a dust excluding member positioned intermediate the bowl and the hollow member, the under surface of said dust excluding member being a reflector by which the light rays passing through the upper part of the hollow member are diffused downwardly within the bowl.

4. In a lighting fixture, a bowl, a reflector the upper portion of which is transparent for the passage of light rays to the upper portion of the bowl and a portion of the outer surface of the reflector being provided with a light reflecting coating, and a dust cap for closing the space intervening the bowl and the reflector, the under surface of said dust cap constituting a light reflecting surface co-operable with the outer coated surface of the reflector for diffusing the light rays downwardly within the bowl. y

5. In a lighting fixture, a dome, a reflector the inner surface of which is mirrored fleeting said light rays downwardly within and the outer surface of which is coated with the dome.

n light reflecting medium, the upper part; In testimony whereof I have hereto 10 of said reflector being transparent for the Signed my name this 28th day of February, passage of light rays to the upper part 1922.

of the dome, and areflecting surface intervening the reflector and the dome for de- LOUIS ROTH. 

